MRI apparatus, NMR analyzer, and gantry

Abstract

A magnetic resonance imaging apparatus includes a static magnetic field generating unit, a main coil (gradient magnetic coil), a radio frequency coil, and a shimming structure unit. The shimming structure unit includes first iron shims and second iron shims. The first iron shims are disposed between the main coil and a shield coil of the gradient magnetic coil and disposed in a central axial center of the static magnetic field generating unit. The second iron shims are disposed on an outer side of the main coil and the shield coil and disposed on a central axial end of the static magnetic field generating unit.

1. A magnetic resonance imaging apparatus comprising:
 a static magnetic field generating unit that generates a static magnetic field within a bore; 
 a gradient magnetic coil that applies a gradient magnetic field to a test subject arranged in the static magnetic field; 
 a radio frequency coil that receives a magnetic resonance signal from the test subject to which the gradient magnetic field is applied; and 
 a shimming structure unit that adjusts static magnetic field uniformity, wherein the shimming structure unit includes
 a first magnetic member disposed between a main coil and a shield coil of the gradient magnetic coil and disposed in a central axial center of the static magnetic field; and 
 a second magnetic member disposed on an outer side of the main coil and the shield coil and disposed on a central axial end of the static magnetic field generating unit. 
 
 
   
   
     2. The magnetic resonance imaging apparatus according to  claim 1 , wherein the second magnetic member is fixed onto an outer peripheral surface of the static magnetic field generating unit. 
   
   
     3. The magnetic resonance imaging apparatus according to  claim 1 , wherein the second magnetic member is fixed onto an end surface of the static magnetic field generating device. 
   
   
     4. The magnetic resonance imaging apparatus according to  claim 1 , wherein the static magnetic field generating unit includes a superconducting magnet, and
 the second magnetic member is fixed onto a vacuum chamber of the superconducting magnet. 
 
   
   
     5. The magnetic resonance imaging apparatus according to  claim 2 , wherein the static magnetic field generating unit includes a superconducting magnet, and
 the second magnetic member is fixed onto a vacuum chamber of the superconducting magnet. 
 
   
   
     6. The magnetic resonance imaging apparatus according to  claim 3 , wherein the static magnetic field generating unit includes a superconducting magnet, and
 the second magnetic member is fixed onto a vacuum chamber of the superconducting magnet. 
 
   
   
     7. The magnetic resonance imaging apparatus according to  claim 4 , wherein the second magnetic member includes a plurality of iron shims aligned in a circumferential direction of the vacuum chamber. 
   
   
     8. The magnetic resonance imaging apparatus according to  claim 5 , wherein the second magnetic member includes a plurality of iron shims aligned in a circumferential direction of the vacuum chamber. 
   
   
     9. The magnetic resonance imaging apparatus according to  claim 6 , wherein the second magnetic member includes a plurality of iron shims aligned in a circumferential direction of the vacuum chamber. 
   
   
     10. The magnetic resonance imaging apparatus according to  claim 4 , wherein the second magnetic member is an iron ring running along a cylindrical shape of the vacuum chamber. 
   
   
     11. The magnetic resonance imaging apparatus according to  claim 5 , wherein the second magnetic member is an iron ring running along a cylindrical shape of the vacuum chamber. 
   
   
     12. The magnetic resonance imaging apparatus according to  claim 6 , wherein the second magnetic member is an iron ring running along a cylindrical shape of the vacuum chamber. 
   
   
     13. The magnetic resonance imaging apparatus according to  claim 4 , wherein the second magnetic member is fixed onto the vacuum chamber with a non-magnetic anchor bolt. 
   
   
     14. The magnetic resonance imaging apparatus according to  claim 5 , wherein the second magnetic member is fixed onto the vacuum chamber with a non-magnetic anchor bolt. 
   
   
     15. The magnetic resonance imaging apparatus according to  claim 6 , wherein the second magnetic member is fixed onto the vacuum chamber with a non-magnetic anchor bolt. 
   
   
     16. The magnetic resonance imaging apparatus according to  claim 1 , wherein the first magnetic member includes a plurality of iron shims and trays that accommodates the iron shims, and the first magnetic member is arranged within the bore in the static magnetic field generating unit. 
   
   
     17. The magnetic resonance imaging apparatus according to  claim 2 , wherein the first magnetic member includes a plurality of iron shims and trays that accommodates the iron shims, and the first magnetic member is arranged within the bore in the static magnetic field generating unit. 
   
   
     18. The magnetic resonance imaging apparatus according to  claim 3 , wherein the first magnetic member includes a plurality of iron shims and trays that accommodates the iron shims, and the first magnetic member is arranged within the bore in the static magnetic field generating unit. 
   
   
     19. The magnetic resonance imaging apparatus according to  claim 1 , wherein the first magnetic member is attached to the gradient magnetic coil provided within the bore in the static magnetic field generating unit. 
   
   
     20. The magnetic resonance imaging apparatus according to  claim 2 , wherein the first magnetic member is attached to the gradient magnetic coil provided within the bore in the static magnetic field generating unit. 
   
   
     21. The magnetic resonance imaging apparatus according to  claim 1 , wherein the second magnetic member is fixed within a range of 0.7 meters to 0.75 meters in a radial direction from a center axis of the static magnetic field generating unit. 
   
   
     22. The magnetic resonance imaging apparatus according to  claim 1 , wherein the first magnetic member is fixed within a range of 20 centimeters in forward and backward directions from an axial center of the static magnetic field generating unit. 
   
   
     23. The magnetic resonance imaging apparatus according to  claim 1 , further comprising a structure that flexibly holds the gradient magnetic coil to serve as a silencing mechanism for suppressing noise generated by the gradient magnetic coil. 
   
   
     24. A nuclear magnetic resonance analyzer comprising:
 a static magnetic field generating unit that generates a static magnetic field within a bore; 
 a gradient magnetic coil that applies a gradient magnetic field to a sample for analysis arranged in the static magnetic field; 
 a radio frequency coil that receives a magnetic resonance signal from the sample to which the gradient magnetic field is applied; and 
 a shimming structure unit that adjusts static magnetic field uniformity, wherein the shimming structure unit includes
 a first magnetic member disposed between a main coil and a shield coil of the gradient magnetic coil and disposed in a central axial center of the static magnetic field; and 
 a second magnetic member disposed on an outer side of the main coil and the shield coil and disposed on a central axial end of the static magnetic field generating unit. 
 
 
   
   
     25. A gantry comprising:
 a static magnetic field generating unit that generates a static magnetic field within a bore; and 
 a shimming structure unit that adjusts static magnetic field uniformity, wherein the shimming structure unit includes
 a first magnetic member disposed between a main coil and a shield coil of a gradient magnetic coil, which applies a gradient magnetic field to a test subject or a sample for analysis arranged in the static magnetic field, and disposed in a central axial center of the static magnetic field; and 
 a second magnetic member disposed on an outer side of the main coil and the shield coil and disposed on a central axial end of the static magnetic field generating unit.